PennEast has upped the size of the natural gas pipeline it plans to route through Northampton County from the originally proposed 30-inch diameter to 36 inches.

And it has filed a more detailed route that takes the pipeline through Moore Township, passing just north of Bath, through Upper and Lower Nazareth townships, into Bethlehem Township just west of Louise Moore Park and past St. Luke's Hospital's Anderson Campus, then west of Route 33, through Lower Saucon and Williams townships.

The pipeline, announced in August, would cross under the Lehigh River just east of Route 33 and the Delaware River just south of Riegelsville in Durham Township.

The company, a consortium that includes UGI Energy Services, says the 108-mile pipeline from Wilkes-Barre to Mercer County, N.J., is needed to bring lower-priced natural gas to homes and businesses in Pennsylvania, New Jersey and beyond and to improve the reliability of the natural gas supply.

Environmentalists say the project isn't necessary, would damage natural lands and wildlife, pose a danger to nearby residents and shouldn't be approved by the Federal Energy Regulatory Commission.

"It's going to be a pretty ugly scar through the region," said Jeff Tittel of the New Jersey Sierra Club, which has called on FERC to reject the application.

New details of the plan were contained in a request PennEast filed with FERC to enter its pre-filing program, a pipeline approval process that streamlines federal review and allows for early public input on the pipeline route and its potential environmental impact.

"The attraction to pre-filing is all the issues can be worked out in the early stages, so when they file their formal application, it can be addressed," said FERC spokeswoman Tamara Young-Allen.

PennEast spokeswoman Patricia Kornick said the route contained in the filing is preliminary and is likely to change before the company files its formal application with FERC next summer. The company filed an overview map offering little detail when it announced the project.

"That has changed even since August," she said. "We have already had some reroutes."

It's unclear from the maps how close the pipeline would pass to St. Luke's Hospital's Anderson Campus off Route 33 in Bethlehem Township, or whether it would touch hospital property.

St. Luke's spokeswoman Denise Rader would not say whether the pipeline would cross any part of the recently opened campus or what concerns that might raise.

"St. Luke's is planning to discuss pipeline plans with PennEast in the near future," Rader said. "Currently no firm decisions have been made."

Between its origin in Dallas, Luzerne County, and Pennington, N.J., the pipeline would affect 861 landowners of 1,094 properties, according to the filing. About 38 percent have granted PennEast surveyors access to their properties to assess potential obstacles.

About a third of the pipeline would be co-located with existing utilities.

Company surveys show several federally listed endangered species are likely to live along the route of the pipeline, including the bog turtle, dwarf wedgemussel, Indiana bat and the proposed-for-listing northern long-eared bat. The company has identified 33 wetlands areas and 60 bodies of water in 11 percent of the 400-foot-wide route it surveyed for the project.

The pipeline also would pass close to several archaeological sites and historic agricultural buildings, and require construction of a 26,000-horsepower compressor station in Kidder Township, Carbon County.